Actually, yes. Spine facing out, books standing vertically for ease of extraction. Common sense, of course. But then I've been using bookcases almost as long as I can remember.
I've thought about whether I should have the lens and end caps on (to prevent dust from getting into lens), or whether to leave them off so that the (presumably) moist air inside will be dried up. I'll probably remove the lens just to relieve stress on the mount, and also for ease of storage. I don't own a dry cab though, I practically live in one, and while here I just keep everything in my camera bag with a large bag of silica gel and hope for the best.